Regulatory trends in water efficiency

By Winston Huff, CPD, LEED AP BD+C

The plumbing industry is slow to change. This can be a good thing, because our health and safety depend on plumbing, but it can also be frustrating when trends need to change. For example: A growing concern is that plumbing professionals design systems only for the health and safety of people at the expense of the environment. Ultimately, however, if the environment suffers, we will all suffer. We must realize that plumbing systems should protect the health and safety of the public as well as protect the environment.

Plumbing systems have evolved to the point that, on a rainy day in a typical community, the stormwater system moves millions, or even billions of gallons of rainwater miles away from people and buildings. On that same day, billions of gallons of drinking water are moved miles in the opposite direction back toward buildings and people. Still on the same day, another plumbing system is moving wastewater away from people and buildings. We call this efficiency. (See the sidebar “Don’t cross the streams.”)

The average U.S. citizen uses more than 130 gallons of drinking water and creates 130 gallons of wastewater a day. Is this an efficient system? How much do these three systems cost our communities in dollars and environmental health?

If we keep using more water, in the future we will have to design systems that handle 200 gallons or more per person per day. Unfortunately, many cities are beyond their limits already, and systems cannot be extended or expanded. As a result, plumbing professionals have seen an increase in demand for plumbing systems that address these problems. Alternate, graywater and rainwater harvesting are topics we discuss every day. These systems are not specialty systems that are used in a few buildings. They are becoming more accepted and are being used as a new standard system by some.

With this growth in alternate water systems comes an increase in regulations. Following is a look at some of the regulatory trends that are currently growing in our plumbing industry.

The EPA and combined sewer overflows

More than 770 communities across the country are implementing long-term control plans to meet U.S. Environmental Protection Agency requirements to reduce the number of combined sewer overflows (CSOs) in their areas. Most communities with CSOs are located in the Northeast, the Great Lakes regions and the Pacific Northwest, affecting approximately 40 million people. (Refer to my column in the January/February 2012 issue of Plumbing Systems & Design for more information.)

If you live in one of these areas, you may see your local community getting ready to spend billions of dollars to fix this problem. Many municipalities are trying to solve the problem with infrastructure changes, such as adding new waste piping in the streets or installing more wastewater storage tanks. However, these solutions are sometimes impossible to build or they carry large price tags.

As an alternative, the EPA is promoting long-term control plans that include green solutions such as rainwater harvesting and green vegetative roof systems, which means that they are asking facility owners to fix some of the problems onsite. In the big picture, these systems can make sense and create a workable solution. In many cases, it is better to use rainwater onsite while reducing drinking water consumption. Local stormwater and wastewater systems are encouraging the implementation of these solutions by providing incentives for low impact development (LID) systems.

Rainwater retention/rainwater harvesting

Many site designers include rainwater retention areas that hold runoff from the site’s green spaces, parking lots, hard surfaces and roof areas in tanks or ponds, but this creates problems for building owners who want to use the area for purposes other than expensive rainwater retention systems. Now many regions are offering incentives such as reduced stormwater charges to developers who install permeable paving. This solution reduces the amount of rainwater runoff, which is a win-win for the building owner and the environment.

Another solution is a rainwater harvesting system that collects rainwater from the roof and reuses it for the building’s plumbing systems, such as flush fixtures, irrigation or mechanical water makeup. For example, a facility that has cooling towers can use one or two million gallons of water per year just for the cooling tower makeup. Installing a rainwater harvesting system can offset the facility’s municipal water charges for the year, because the water is not being purchased from the local water utility. It also helps reduce sewer charges. An added bonus to the owner is the smaller size of the rainwater retention area, which gives the owner more site area to use and reduces site costs.

In CSO areas, the local government may offer financial incentives to offset the cost of installing a rainwater harvesting system. This can be a win for the owner because it reduces both construction costs by reducing the size of the retention area and operations costs by reducing municipal water usage. It benefits the city, because the system reduces the demand on stormwater and water distribution systems. It is a benefit to the environment by reducing stormwater flows, reducing drinking water withdrawals from natural water sources and reducing energy use.

Regulatory requirements are constantly changing, so you must always check with the local regulatory agency before starting a project. Here is a short list of some of the items they might require:

• A method to drain the rainwater cistern when the water is not being used — For example, if rainwater is used for cooling tower makeup, the facility may need to drain the rainwater tank mechanically in the winter when the tower is not in use.

• A method to drain the cistern during back-to-back storm events — Some manufacturers offer controls that follow biometric atmospheric pressures and drain tanks between two storm events.

• Underground tank installation standards — This can include nontoxic interior surfaces, burial standards or materials.

• Nontoxic or safe roof materials — Water used in buildings can off-gas harmful chemicals collected from roofs.

• First flush diversion

• Water treatment

• Testing quality standards and schedules

• Monitoring and metering standards

• Cross-connection controls

Also, determine whether the system will be required to meet NSF/ANSI 350: On-site Residential and Commercial Reuse Treatment Systems, and if it needs to be covered by the facility’s insurance plan.

Green roofs

Some regulatory agencies are encouraging the installation of green vegetative roofs with incentives because of the benefits that green roofs offer municipal storm water systems. Green roofs include plants and growth media that collect the first few inches of rainfall. The plants then transform the water through evapotranspiration into the atmosphere. The growth media also can act as a filter to clean the rainwater as it passes through; as a result the stormwater flowing into the municipal system is a higher quality.

Again, you must review local regulatory agency requirements before starting the project. Following are some of the items that will affect the building’s plumbing system design:

• Irrigation system — Some green roofs require constant irrigation. If so, a rainwater harvesting system can be used to provide irrigation to the plants.

• Temporary irrigation — Most green certifications such as LEED discourage permanent irrigation systems. However, they will allow a temporary irrigation system that will be used during the first year until the plants are established.

• Roof drain and plant system drainage interconnections

• Access for fire protection staff during a fire event

• Hose connections for periodic roof washdown

Other regulations and standards

Plumbing designers should learn about all of the industry standards that relate to their projects, not just the local regulatory agency requirements. For example, ANSI/ASHRAE/USGBC/IES 189.1: Standard for the Design of High-Performance Green Buildings Except Low-Rise Residential Buildings includes standards for water systems. Other industry standards require the installation of water meters for the different systems in a facility that can be connected to a data monitoring and storage system. These standards require the operations team to collect data at preset times.

Water-free waste systems

Another trend is the use of waste systems that do not require water. Most waste systems use water to transport the waste from one point to another, but is this the best way to transport and treat waste? One alternative is the way waste has been treated naturally for thousands of years: composting.

Some composting systems can collect the nutrients in waste and use them where they are needed, such as for landscaping. Like any waste system, a composting system must be installed and maintained properly. If these systems are used, they should meet a standard such as NSF 41: Non-Liquid Saturated Treatment Systems. According to NSF, “Standard 41 is for treatment systems that do not utilize a liquid-saturated media as a primary means of storing or treating human excreta or human excreta mixed with other organic household materials. These would include composting toilets and similar treatment technologies.”

While composting systems may not be a viable option in some areas today, they are an important consideration as we look to the future of net-zero water and waste systems. They are very simple when compared to our modern complex municipal systems.

Conclusion

The future is here. Rainwater harvesting, graywater systems, and green vegetative roofs are no longer niche markets. We all need to know how to design safe plumbing systems to support them.

Winston Huff, CPD, LEED AP BD+C, is a project manager, plumbing fire protection designer and sustainable coordinator with Smith Seckman Reed Consulting Engineers in Nashville, Tenn. He serves as an ASPE representative on the ICC Green Construction, Energy and Water Code Development Committee and is on the U.S. Green Building Council’s Water Efficiency Technical Advisory Group. He was the founding editor of Life Support and Biosphere Science and has served as its editor-in-chief. He also is editor of Me Green You Green (megreenyougreen.com), a LEED credit databank.
Correction: Last month’s article referred to the next edition of LEED as “LEED 2012,” which was scheduled for release after USGBC members voted later this year. The term “LEED 2012” was a working title used during development, but the USGBC has since changed the title to “LEED V4.0” and delayed issue until 2013. The intent of last month’s column was to update readers on the new credits under development; the final issue may be different.

Winston Huff, CPD, LEED AP BD+C, is a project manager, plumbing fire protection designer and sustainable coordinator with Smith Seckman Reed Consulting Engineers in Nashville, Tenn. He serves as an ASPE representative on the ICC Green Construction, Energy and Water Code Development Committee and is on the U.S. Green Building Council’s Water Efficiency Technical Advisory Group. He was the founding editor of Life Support and Biosphere Science and has served as its editor-in-chief. He also is editor of Me Green You Green (megreenyougreen.com), a LEED credit databank.